Robustness analysis of cellular memory in an autoactivating positive feedback system.
Cellular memory is a ubiquitous phenomenon in cell biology. Using numerical simulation and theoretical analysis, we explored the robustness of cellular memory to intrinsic noise in a transcriptional positive feedback system. Without noise, the system could create two stable steady states and function as a memory module. Memory robustness index and mean first-passage time were used to quantify the robustness of memory. Large cell size and strong cooperativity in binding enhanced memory storage remarkably. Adding a second positive feedback loop improved persistent memory significantly, whereas including a negative one destabilized memory storage. These are consistent with experimental observations. We interpret why positive feedback loops are actively involved in epigenetic memory from a dynamical systems perspective.
Cheng
Zhang
Z
National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University, Nanjing 210093, China.
Liu
Feng
F
Zhang
Xiao-Peng
XP
Wang
Wei
W
D002468:Cell Physiological Phenomena / Q000235:genetics*; D048429:Cell Size; D044127:Epigenesis, Genetic; D025461:Feedback, Physiological / Q000235:genetics*; D008957:Models, Genetic; D014158:Transcription, Genetic